J. Tamaoki et al., EFFECT OF AZELASTINE ON SULFUR-DIOXIDE INDUCED IMPAIRMENT OF CILIARY MOTILITY IN AIRWAY EPITHELIUM, Thorax, 48(5), 1993, pp. 542-546
Objective-The effect of azelastine on airway mucociliary transport fun
ction was studied by measuring ciliary motility of human bronchial epi
thelium in vitro with a photoelectric method. Method-Bronchial epithel
ial cells were obtained by fibreoptic bronchoscopy, mounted in a Rose
chamber, and perfused with Krebs-Henseleit solution. The preparations
were placed on a microscope stage equipped with an illuminator, and th
e variations of light intensity caused by ciliary beating were detecte
d by a photometer. Results-The addition of azelastine to the perfusate
increased ciliary beat frequency (CBF) in a dose dependent manner wit
hout ciliary discoordination. The mean (SE) maximal increase from the
baseline value and the concentration required to produce a half maxima
l effect were 27.0 (4-2)% and 9.2 x 10(-6) mol/l, respectively. Exposu
re of the cells to the perfusate containing 3 ppm sulphur dioxide rapi
dly decreased CBF by 59.2 (5.0)%, and was accompanied by a reduction i
n intracellular cyclic AMP levels from 38.1 (4.3) to 10.1 (2.4) pmol/m
g protein. This effect was prevented by pretreatment of cells with aze
lastine in a dose dependent manner. Conclusions-Azelastine not only st
imulates ciliary motility of airway epithelium and hence mucociliary t
ransport function, but may also protect against sulphur dioxide induce
d ciliary dysfunction, probably by inhibiting intracellular cyclic AMP
loss.